An accounting firm is planning for the next tax preparation season. From last years returns, the firm collect a systematic random sampleof 100 filings. The 100 filings showed an average preparation time of 90 minutes with a standard deviation of 140 minutes.

March 3, 2015

An accounting firm is planning for the next tax preparation season. From last years returns, the firm collect a systematic random sampleof 100 filings. The 100 filings showed an average preparation time of 90 minutes with a standard deviation of 140 minutes.

An accounting firm is planning for the next tax preparation season. From last years returns, the firm collect a systematic random sampleof 100 filings. The 100 filings showed an average preparation time of 90 minutes with a standard deviation of 140 minutes.

An accounting firm is planning for the next tax preparation season. From last years returns, the firm collect a systematic random sampleof 100 filings. The 100 filings showed an average preparation time of 90 minutes with a standard deviation of 140 minutes. What is the probability that the mean completion time will be more than 120 minutes? What is the probability that the mean completion time is between 1 and 2 hours, i.e., 60 and 120 minutes?